An intensive, longitudinal study of two cohorts of 25 four-year- olds is proposed. The development of social popularity and unpopularity among these children will be the object of study. Social rejection or isolation in childhood has been found to be associated with social, cognitive, and physical problems in later life. The main contribution of this research project will be an improved understanding of the development of consistent sociometric status in young children. Longitudinal data-collection will permit repeated assessments to be made, and causal conclusions to be drawn. The entry and rejection strategies children employ will be examined in two settings: spontaneous contact episodes on the preschool playground, and experimentally established small-group analogue entry tasks. Video-recordings will be made, and detailed transcripts generated of children's social interchanges in these settings. Sociometric interviews will be conducted, in order to classify the children in terms of their popularity status. The development of social cliques and popularity groups during the year at preschool will be examined. A range of quantitative analyses of the entry and rejection strategies will be carried out, together with hypothesis-generating hermeneutic or interpretive analysis. The question of whether rejected preschool children differ from their popular peers in the extent of their social skills, or in their style of interaction in entry situations, will be addressed. Incidence of behavioral problems, as reported by parents, will be compared for children of different sociometric status. The long- term aim of the project is, by means of a longitudinal design and multiple assessment methodologies, to provide knowledge of young children's behavior which will guide the future design and implementation of intervention programs to alleviate social rejection among young children.